1.Although the sign was infront of Huy,he didn't notice it.
2.Becasue his father is too old, he’s learning to run the family workshop.
3.As soon as she had opened the letter, she burst into tears.
4.I’m looking forward to seeing my mother in Hanoi.(look forward to+V-ing)
5.Where should we go for holidays?” She asked.
6.I don’t know what to do in order to lose weight.
7.She said she had been very tired.
8.She told Ben to be careful.
9.Sally is older than Bob.
10.You spent more money than me.